First Time Using Owner Financing

[Samuel Fletcher Hardy]

Hey guys I am about to use owner financing for the first time. I have ran all the numbers on the deal 1000 times and am satisfied. The property is owned by a young Realtor and this will be her first time as well. What paperwork do I need to have and documentation do I need to insure I am protected? I don't want to miss something and my down payment disappear.